RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Temsirolimus may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Drugs used in chemotherapy, such as temozolomide, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. It is not yet known whether radiation therapy is more effective when given together with temsirolimus or temozolomide in treating patients with glioblastoma.